[whatwg] createImageData should take unsigned long

Philip Jägenstedt philipj at opera.com
Fri Sep 4 03:32:58 PDT 2009

On Fri, 04 Sep 2009 02:44:25 +0200, Oliver Hunt <oliver at apple.com> wrote:

> On Sep 3, 2009, at 4:50 PM, Robert O'Callahan wrote:
>> On Fri, Sep 4, 2009 at 4:48 AM, Oliver Hunt <oliver at apple.com> wrote:
>> On Sep 3, 2009, at 4:54 AM, Ian Hickson wrote:
>> Yeah, that seems likely, since none of you implemented the higher-DPI
>> ImageData in your first versions. :-(
>> WebKit's implementation has always worked with high dpi backing
>> stores and follows the spec accordingly.
>> Under what circumstances do you use more than one device pixel per
>> CSS pixel? Does it require the user to turn on UI scaling on Mac?
>> Regardless, I bet that most people using Webkit to write scripts
>> using getImageData still get it wrong, because they have normal
>> screens. Implementing high-res backing store in more browsers won't
>> solve this problem, not until the average developer has a high-dpi
>> screen. But I repeat myself.
> Indeed -- i was merely commenting that there was actually a "correct"
> implementation -- i am still of the opinion that exposing image data
> was a bad thing and that a filtering API would have been superior.  Oh
> well, the past is the past and we must now live with it. :-/

How can one use this implementation? In my tests getImageData(0,0,w,h)  
simply returns a wxh ImageData object. It would be interesting to enable  
this non-1:1 backing store to see if sites break or not.

Philip Jägenstedt
Core Developer
Opera Software

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